MK5 Golf GTI

All Things Mk5 => Modifications & Technical Area => Technical Workshop => Topic started by: fliprio on April 20, 2012, 08:23:22 pm

Title: Air Con Problems - should the fan cut in?
Post by: fliprio on April 20, 2012, 08:23:22 pm

Hi all,

I have been having some problems with the air con on my mk5 Gti that I have just purchaced

When I first got it, it wouldnt work, took it back to the garage and they took it to VW to be reset - they said that this was simply hooking it up to the diagnostics and reseting something that then made it work and VW confirmed it was working.

Went to pick it up today and it still doesnt work, the technican at the garage I purchaced the car from said it did work, so when I asked him what the temperature of the air coming out the vent he confirmed that his little aircon tool thing said 19 degrees with it set on low, since it was only 10 degrees out today I think we can safley say it isnt working!

Does anyone know what VW would have done to reset something?  Also, neither of the fans in front of the radiator are cutting in when you turn the aircon on (I thought they were meant to come on?) you can hear a slight engine pitch change when you have the aircon on, so I would assume that the magnetic clutch is engaging the compressor, but a bit lost as to what it could be and the garage dont seem to be too cleaver if they think a working aircon system should only go down to 19 degrees when its 10 degrees outside!

Thanks in advance

Title: Re: Air Con Problems - should the fan cut in?
Post by: bacillus on April 20, 2012, 10:53:37 pm

Yup, small radiator fan should be spinning when you run the ac.

I suspect that your compressor has gone bad which isn't uncommon for the earlier gtis. Look at item number 6 in this link http://www.golfmkv.com/forums/showthread.php?t=24952

Title: Re: Air Con Problems - should the fan cut in?
Post by: fliprio on April 20, 2012, 11:35:34 pm

If the compressor had gone, wouldnt the Fan be cutting in, but simply not going cold?  I thought the pressure switch powered both the fan and the compressor clutch, so no gas/pressure = no fan or driving of the compressor?

Title: Re: Air Con Problems - should the fan cut in?
Post by: fliprio on April 21, 2012, 10:26:38 am

anyone had this type of fault before?  I have read somewhere that the compressor has a saftey clutch on it, which shears when the shaft fails (which I think is the common failure shown in that link) once this has happened, I would assume I shouldnt hear the slight rise in idle RPM when switching on the aircon?

Title: Re: Air Con Problems - should the fan cut in?
Post by: perky85 on April 22, 2012, 03:25:54 pm

Get the aircon system vacuumed & regassed & check for leaks.

Low refrigerant in the circuit can also cause failure of aircon to work

Title: Re: Air Con Problems - should the fan cut in?
Post by: fliprio on April 22, 2012, 08:22:29 pm

it was regassed last, I supose it could loose it quickly if there was a massive leak.

Aircon fan seems to work as it came on with the main coolant fan today when it got hot, just doesnt come on when the aircon is switched on.